Year

1993

Degree Name

Master of Science (Hons.)

Department

Department of Chemistry

Abstract

This thesis is presented in two parts. Part 1. Asymmetric Synthesis via Chiral Sulfoximines. Chapter 1. Asymmetric Synthesis of Chiral Alcohols and Ketones from Sulfoximines The application of chiral sulfoximines to the asymmetric synthesis of chiral alcohols and ketones is described historically in Chapter 1. Chapter 2. Asymmetric Synthesis of Chiral Alcohols and Chiral Ketones from (+)-(S)-N-t- B u t y l d i p h e n y l s i l y l - S - M e t h y l - S-Phenylsulfoximine. The synthesis and applications of (+)-(S)-N-t-butyldiphenylsilyl- S-methyl-S-phenylsulfoximine to the asymmetric synthesis of chiral alcohols is described in Chapter 2. The diastereoselectivities of all these reactions have been documented. The stereochemistry of some major adducts was determined by X-ray crystallography. Two racemic ketones, 2-tbutyl- cyclohexanone and 2-methyl-cyclohexanone were successfully resolved by diastereoselective addition of lithiated (+)-(S)-N-t-butyldiphenylsilyl-S-methyl-S-phenylsulfoximine, followed by separation of the diastereomeric adducts and then thermolysis. Chapter 3. Diastereoselective Conjugate Addition Reactions of Lithiated Allylic Sulfoximine to Cyclic and Acyclic Enones. The asymmetric conjugate addition reactions of racemic S-allyl S-phenyl-N-tosylsulfoximine with Michael acceptors and carbonyl compounds is described in Chapter 3. The diastereoselective ratio of all reactions have been documented. The stereochemistry of two major adducts was determined by Xray crystallography analysis. Part 2. Diasteroselective Synthesis of p-Azido Sulfoxides. Chapter 4. Addition of Nitrogen Nucleophiles to Vinyl Sulfoxides. A survey of the conjugate addition reactions of vinyl sulfoxides with nitrogen nucleophiles is described. Chapter 5. Addition of Azide to Vinyl Sulfoxides. The conjugate addition reaction of azide ion to p - a r y l - a - phenylsulfinylacrylates is reported in Chapter 5. Reactions in the presence of acetic acid gives triazoles while reactions in the presence of hydrochloric acid gives p-azido esters. These are the first p-azido sulfoxides to be isolated.

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